If there isn't one already, why not add a test case to see whether or not a solution correctly returns a new array, per the instructions? A few of the Java solutions I saw were destructive.

Read the problem more thoroughly! Note that the diameters of each circle were given, and you calculated radii.

Using python; a small typo in the sample test cases caught my eye. For your 'T2' assertion, the subsequent string misspells 'triple' as 'tripple.'

Great kata, thank you!